Implement new login page layout
Fix #40 (closed)
We can add a video later, but I think it looks nice as it is for now.
It's responsive, of course:
I took the opportunity to upgrade to Bootstrap 5, which explains some of the changes -- notably the --bs prefixes for CSS variables, and the fact that I had to tweak some of the colours because Bootstrap 5's cyan has a different shade:
Edited by Axel Bocciarelli